Tesla is abandoning the 75kWh battery pack for both the Model X and Model S, CEO Elon Musk announced on Wednesday. Customers have until Sunday, January 13th to place orders if they want cars fitted with the company’s lowest-capacity (and cheapest) battery.

The 75kWh pack is what Tesla uses in the base model of both those cars, which means they will now only be available with the higher-capacity 100kWh pack. That also means the price to buy either car is about to increase dramatically. Unless new variants are in the works, or Tesla changes its prices — something it does often, to be fair — the base price of the Model S is about to increase from $76,000 to $94,000, while the cost of the cheapest Model X is about to jump from $82,000 to $97,000.

A spokesperson for Tesla declined to comment.

Starting on Monday, Tesla will no longer be taking orders for the 75 kWh version of the Model S & X. If you’d like that version, please order by Sunday night at https://t.co/46TXqRJ3C1

The change should help differentiate the Model S and Model X from the Model 3, which currently starts at $44,000, but can run as high as $70,500 with options. The currently available versions of the Model 3 use a 75kWh battery pack, but it uses differently-sized cells.

Tesla has tinkered with the price and configuration of its cars a lot over the years, and has also added and eliminated a number of different battery capacity options. It introduced the 75kWh battery pack in 2016 as a cheaper compliment to the 90kWh option that was being sold at the time. Tesla has offered as small as a 40kWh battery for the Model S, and as large as the 100kWh version for the S and X that’s still on sale. The company at one point also offered 60kWh and 70kWh packs for the Model S, though those were just software-limited versions of the 75kWh pack. (Customers could even pay Tesla to “unlock” that extra range.)

It’s been years since Tesla only offered one battery option for these models, though. The timing of Musk’s announcement is also curious. Just last week, Tesla lopped $2,000 off the cost of all of its cars to compensate for the fact that they’re now only eligible for half of the $7,500 federal EV tax credit.

Musk told a Twitter user that Tesla is “Def not” phasing out the Model S or X any time soon. Another user asked if the change means Tesla is going start promoting these cars more like the Model 3, which is offered in “Long Range,” “Performance,” and (eventually) “Standard Range” variants, instead of by battery pack size. “Yes,” Musk replied.